China on Monday dispatched a team of investigators to Malaysia to probe two passengers using stolen passports to board the missing Beijing-bound MH370 flight amid mounting speculation that a terror link was behind the mysterious disappearance of the aircraft.

Latest reports said that for the first time since it disappeared more than two days ago suspected wreckage of the Boeing 777 flight with 239 passengers on board was spotted off the Vietnam coast.

The flight had taken off Kuala Lumpur but lost contact with Air Traffic Authority in Vietnam soon after flying over the coast of the country.

More than 40 ships and 34 aircraft from nine countries were involved in the mission to locate the mysteriously disappeared aircraft. More countries are now sending vessels to pitch in with the efforts.

“China's Ministry of Public Security (involved in maintaining the country’s internal security) has decided to send a work team to Malaysia to investigate two people using stolen passports to board a Beijing-bound plane that has been missing,” the official Xinhua news agency reported.

The decision followed Interpol's confirmation that two passengers boarded the plane operated by the Malaysian Airlines with stolen passports and was made after a consultation with the Malaysian authorities who called for a joint investigation into the matter, said the ministry late Sunday.

The 13-member group comprises officials with the Ministry of Foreign Affairs, Ministry of Public Security, Ministry of Transport and Civil Aviation Administration of China (CAAC).

“The most pressing and important work remains search and rescue,” said Guo Shaochun, deputy head of the Department of Consular Affairs with China's Foreign Ministry; he is also heading the Chinese group headed to Malaysia.

“We will call on the Malaysian side and other foreign parties involved in the rescue work to work together with Chinese planes and ships, to intensify research and rescue efforts, strengthen coordination and not to give up only if there is any hope,” Guo said.

It has emerged that two Chinese citizens had bought the tickets together through China Southern Airlines and were to fly onward to Europe.

Speculation about terror links to the aircraft’s disappearance was spreading on Chinese social media with some connecting it to an incident last year when the Malaysian government deported a group of ethic Uyghurs back to China. The Chinese government has blamed the Kunming stabbings earlier this month that left 34 dead more than 140 injured to separatists from the Xinjiang Uyghur Autonomous Region (XUAR).

A senior Malaysian police official defended the government's actions in comments to AFP, saying the Chinese nationals, all members of the Uyghur ethnic minority, were involved in a human-smuggling syndicate.

The state media has also apparently tried to conceal the identity of Uyghur painter who was part of a Chinese group of artists returning to Beijing on flight MH370 after an exhibition in Malaysia last month.

There is no direct link or explicit evidence yet about terrorists taking down the aircraft but it’s natural that Chinese authorities would want to fully investigate the flight’s disappearance as so many of its citizens were travelling in it.

Beijing has dispatched two more ships and two more helicopters to search for the aircraft, state media said Monday.

Xinhua reported that “Marine Police 3411" -- a Chinese marine police vessel in search of the Beijing-bound plane, had covered a 200-sq-km area by Sundya night.

The vessel relies on strong searchlights and night vision equipment to search around the clock in a wider area and it also taking into account expert analysis on the sea area's currents and wind speeds.